A Safer Knife

This quote was in the Stiletto thread going on over here - http://www.thehighroad.org/showthread.php?t=720007.

My first reaction was to laugh but it was amazingly handy. I could sit/stand/twist around getting bumped and tossed without worrying about cutting myself. When I needed to use it, *click*cut*click* ... the live blade stayed out maybe 1-2 seconds tops and then went away like magic.
That got me thinking about a recent experience:

I got my first OTF automatic, a Microtech Ultratech D/E (double edge) at Blade earlier this month. After playing with it for a bit, I was discussing with hso (we were both volunteering with knife rights) that I'd realized how safe it actually was since one's fingers never contact the blade when opening or closing, and unlike a folder one's fingers never cross the path of the blade when closing. hso is an hso (health and safety officer) for a large industrial organization; he's literally a professional safety expert. He elaborated to me that what I'd realized about that Microtech has long been an argument by safety experts in favor of fully legalizing OTF automatics and gravity knives*. That is, they can be safely and quickly opened and closed with one hand, the hand and fingers never need to contact the blade, retracting the blade is easier and safer than closing a folder or even sheathing a fixed blade, and they're usually fully ambidextrous.

* hso advocated for OTF gravity knives in particular since they don't have the spring system that's often temperamental in knives that aren't built to the standards adhered to by Benchmade, Microtech, and the other premium makers. In other words, there's less to break or go wrong with a gravity knife, and a gravity knife can be manufactured at significantly lower cost than an comparable quality automatic.

and unlike a folder one's fingers never cross the path of the blade when closing.

There are plenty of folders that don't need your fingers in the blade path to close. The axis/arc/CBB lock designs are a good example.

ugaarguy

June 19, 2013, 11:15 PM

I'll elaborate further then. You barely have to change your grip to close an OTF DA auto or gravity knife (particularly DA autos with a spine mounted switch like the Microtech Ultratech and Troodon, and the Benchmade HK Tumult and Epidemic), but you have to significantly alter your grip to close a folder. Your fingers are not in the path of the blade should the lock fail on an OTF opener, which they will be when using a folder. You can close an auto closing (aka Double Action) OTF opener much more quickly than you can a folder, and with a strong DA OTF auto knife orientation doesn't matter - as in the spring in the Ultratech is strong enough to close the knife even when the blade is pointed straight down.

I'm also intimately familiar with the Axis lock, and by extension pretty familiar with Spyderco's CBB lock. I'm also familiar with Spyderco's compression lock, and Benchmade's Nak Lok. I know full well that the Axis, CBB, and Compression locks are far stronger and more rugged than the locks on any OTF Auto. But I didn't say stronger or tougher knife, I said safer knife.

Sentryau2

June 20, 2013, 05:17 AM

I had an OTF switchblade go off in the pocket of my swimming trunks (thin mesh pockets) Needless to say after that scare I do not carry automatics. To each his own tho, I could see where an automatic knife could be handy, another thing to look at would be the wave system and similar type opening systems.

RTR_RTR

June 20, 2013, 05:22 AM

I had an OTF switchblade go off in the pocket of my swimming trunks (thin mesh pockets) Needless to say after that scare I do not carry automatics. To each his own tho, I could see where an automatic knife could be handy, another thing to look at would be the wave system and similar type opening systems.

I once took a leak with a cat in the bathroom. Some mistakes only need be made once ;)

ugaarguy

June 20, 2013, 06:32 AM

I had an OTF switchblade go off in the pocket of my swimming trunks (thin mesh pockets) Needless to say after that scare I do not carry automatics. To each his own tho, I could see where an automatic knife could be handy, another thing to look at would be the wave system and similar type opening systems.

What particular OTF automatic? Was it a push button switch, or a sliding switch? Autos like the Infidel and Ultratech need moderately heavy pressure applied linearly over a short distance on the slide switch. In other words, it's a very deliberate movement that's almost impossible to engage accidentally. All OTF autos are not created equally, and that's why we need to know more about the knife in question.

The Wave mechanism is far easier to open unintentionally, either fully or partially, than a high quality DA OTF auto. A partially opened, unlocked blade that you didn't have control of to start with is another safety hazard all together. The Wave system also does nothing to change the closing of blade, and fingers being in the path of the blade on closing.

I'm not running out and getting rid of all my folders by any stretch. I'm perfectly comfortable with the safety of a good locking folder when used with even minimal caution. I just started this thread as an observation of how the oft vilified OTF auto can actually offer an even greater margin of safety than the assumed friendlier traditional locking blade folder.

hso

June 20, 2013, 06:54 AM

I've handled just about every lock design ever put into production on folders and I'm comfortable saying that there are many today that are rock solid with their only chance of failure to lock open either having to do with user error to engage the lock fully or with a manufacturing quality failure.

OTOH, any swing blade has the potential to close on part of the hand when disengaged IF the fingers are between the blade and the body. Not so with a fixed blade (D'uh) or an OTF. That's why self retracting safety utility knives use a manual OTF design with a return to close spring that requires the user to keep the blade extended against that return to close spring. http://www.youtube.com/watch?v=Tlurhh3qJ28 http://www.youtube.com/watch?v=LmyyVUjz4Tc

Any OTF auto or assist, Taylor Cutlery's AO OTF is a pretty clever gizmo, risks opening unsafely because of the mechanism's spring to push it open having to be locked closed. Release the lock, or pass the bias point, and the blade opens whether you meant it to or not. A manual OTF without that spring to open lacks the same potential to open without actively engaging it and because the blade doesn't scissor close there's no place for fingers to get sandwiched between blade and grip.

Luckily, injuries from this sort of mishap are some of the least severe you can have with a knife since the bite of the blade is on the back boney part of the fingers. As such there isn't a lot of motivation in the industry to put self retracting recreational knives out on the market.

ugaarguy

June 20, 2013, 03:39 PM

hso, Thanks for dropping in here. The trigger bar / lever on that Medoc is slick. I'd like to see that concept applied to a recreational knife, with a conventional sporting / recreation blade, and the ability to lock the blade open for sharpening.

zhyla

June 20, 2013, 05:50 PM

Your fingers are not in the path of the blade should the lock fail on an OTF opener, which they will be when using a folder.

Again, there are many folder designs where a lock failure cannot result in sliced fingers. Several Spydercos (Manix 2, for instance) have designs that prevent this.

I'm pretty sure this is all irrelevant. I've cut myself several times and it was never closing a knife, or it closing when it shouldn't. It's usually just me doing stupid things or surprising interactions with the material I'm cutting. I expect that most knife injuries are not going to be prevented by some fancy switchblade.

I wholeheartedly support fancy switchblades being legal.

Sentryau2

June 20, 2013, 06:19 PM

I cannot remember the exact model its been a year or two. I do remember it was benchmade (one of the few expensive knives ive owned) It was mostly my fault (I was swimming with it in my pocket) but I always carry a knife when im swimming so soon after I replaced that knife with a crtk m16 knife I doubt it would have done serious damage but id rather not have any damage at all to that particular area ;)

hso

June 20, 2013, 08:14 PM

a lock failure cannot result in sliced fingers. Several Spydercos (Manix 2, for instance) have designs that prevent this.

zhyla,

I'm confused by that statement. If and folder lock fails while you're holding it in your hand it doesn't matter who makes it since the fingers are still in the way of closure. Help me understand what you're meaning since I'm sure you "see" what you mean to say.

As to your personal experience in not cutting yourself closing a knife, I've seen it 3 times. One with a fully serrated Spyderco Police that resulted in a trip to the ER because not only did the Officer foolishly release and hold the back lock and allowed the blade to fall onto his fingers, but in reaction to the "bite" proceeded to snatch the hand out of the steel toothed jaw. Messy. Noisy, too. It took a whole roll of kerlix out of the kit to get him out the door. The other two times were far less dramatic, but all of them were due to the operator improperly handling the lock as opposed to material or design failures. That shouldn't be surprising though since I've been involved in collecting and the industry for many years and have literally handled hundreds of different knives and seen thousands so I've had several "normal" lifetimes of experience compressed into a few decades.

And I agree it is a relatively minor problem and usually self inflicted.

Sam Cade

June 20, 2013, 08:29 PM

One with a fully serrated Spyderco Police that resulted in a trip to the ER because not only did the Officer foolishly release and hold the back lock and allowed the blade to fall onto his fingers, but in reaction to the "bite" proceeded to snatch the hand out of the steel toothed jaw. Messy. Noisy, too.

I have seen this exact same scenario play out with a fully serrated Cold Steel Vaquero.

When he snatched his fingers back the recurve on the blade severed a tendon.

What makes it worse was that it happened at his own wedding reception. :eek:

zhyla

June 21, 2013, 12:26 AM

I'm confused by that statement. If and folder lock fails while you're holding it in your hand it doesn't matter who makes it since the fingers are still in the way of closure. Help me understand what you're meaning since I'm sure you "see" what you mean to say.

Sorry, I should have posted a picture and been more descriptive. Here's a Manix 2:

http://www.knifeworks.com/images/products/detail/C101G2.jpg

Observe where your index finger will be while gripping this knife. It will either lie in the forward choil (saber grip) or in the coil behind it (most comfortable for hammer grip). If the lock fails anything in either choil will get pinched but not sliced. The same is true for reverse grips with your pinky finger in either choil. It's more obvious with the knife in your hand but the portion of the blade that makes up the forward choil rotates around to mate with the secondary choil.

It's a safety feature that has cropped up in numerous modern Spyderco designs. I thought I had seen a Benchmade with this feature but I'm having a hard time finding an example.

Make sense? I'm sure you can still hurt yourself despite this feature. With this knife in particular a natural position for releasing the lock has those choils clear of features but possibly a ring or pinky finger hanging across the blade path.

ugaarguy

June 21, 2013, 02:05 AM

It's a safety feature that has cropped up in numerous modern Spyderco designs.
Sorry, but I'm not buying it. It's just a finger choil used to choke up on the blade. They're on fixed blades too. Ohh, and the Spydercos with the finger choil blade and corresponding spine jimping are some of my favorites - especially the ones with full flat ground blades. In fact, a Manix 2 LW will very likely be my birthday present to myself in a couple weeks.

Like I said, I'm not running out to get rid of my folders. The thread started as an observation of how DA OTF Autos (and by extension various auto retracting knives) can be safer under some circumstances. Perhaps I should have titled the thread "Observations on the Increased safety of DA OTF Switchblades"

RTR_RTR

June 21, 2013, 03:03 AM

Has anyone actually had a folder lock fail on them? On a knife that cost more than 10 bucks. I don't see why you'd ever have a lot of force on the back end of the blade to start with. Just curious

hso

June 21, 2013, 07:10 AM

Ok, I understand what you're saying.

I agree that the first choil would function exactly as you've described (I've handled this one too) stopping the blade on the tang with the finger. If the grip were further back with the index finger in the second choil you wouldn't have that protection, but I don't see or remember that being the comfortable grip (and it would be used mostly for snap cuts to get the extra forward length and balance). I also agree there are some other folders that use this approach as well as Spyderco, but as you've indicated they're hard to find.

Most folders are designed with as much cutting edge as possible and buyers complain when a substantial ricasso/tang is left. They dislike the "lines" breaking the flow of the blade to and through the grip produces. That's why we don't see companies using this design element. Spyderco's design philosophy has always been different and the hump and hole isn't odd to their users so they can incorporate a choil into the ricasso on a folder without a lot of resistance. That being said, the majority of their knives don't so that we can be faced with the same problem with them that we may be with other knives.

Torian

June 21, 2013, 09:11 AM

This quote was in the Stiletto thread going on over here - http://www.thehighroad.org/showthread.php?t=720007.

That got me thinking about a recent experience:

I got my first OTF automatic, a Microtech Ultratech D/E (double edge) at Blade earlier this month. After playing with it for a bit, I was discussing with hso (we were both volunteering with knife rights) that I'd realized how safe it actually was since one's fingers never contact the blade when opening or closing, and unlike a folder one's fingers never cross the path of the blade when closing. hso is an hso (health and safety officer) for a large industrial organization; he's literally a professional safety expert. He elaborated to me that what I'd realized about that Microtech has long been an argument by safety experts in favor of fully legalizing OTF automatics and gravity knives*. That is, they can be safely and quickly opened and closed with one hand, the hand and fingers never need to contact the blade, retracting the blade is easier and safer than closing a folder or even sheathing a fixed blade, and they're usually fully ambidextrous.

* hso advocated for OTF gravity knives in particular since they don't have the spring system that's often temperamental in knives that aren't built to the standards adhered to by Benchmade, Microtech, and the other premium makers. In other words, there's less to break or go wrong with a gravity knife, and a gravity knife can be manufactured at significantly lower cost than an comparable quality automatic.
I don't have a OTF automatic yet...that Microtech Ultratech D/E is a nice blade!

I think I now understand what the OP is talking about. I've never had issues with auto folding knifes accidentally deploying, or locking mechanisms failing under heavy use, or getting cut with them unless I was doing something stupid.

All the autos I've used have safeties built into them, and even with the safety off, it will requires significant force to actually engage the blade. I currently use the Gerber Applegate Fairbairn Covert Auto (the knife I was discussing in another thread with HSO).

JShirley

June 21, 2013, 09:46 AM

ugaarguy, Spyderco literature mentions that choil as a safety feature on the knives its on.

hso

June 21, 2013, 10:17 AM

John,

Do you recall if they incorporated that for the first time on their UK Pen Knife slip joint or had they used it elsewhere before that?

JShirley

June 21, 2013, 10:24 AM

Oh, no. I recall them saying the choil on the Native was a safety feature, years ago.

ugaarguy

June 21, 2013, 09:45 PM

That's interesting info John. I stand corrected. I'll concede that the index finger would just get crushed rather cut under the high strain that would likely present if the lock was to fail.

On the other hand, everyone wants to focus on lock failure, which I've already stated even I think is a remote possibility on quality knives*. My main point, for the hundredth time, is that the combination of rapid opening closing, with little to no change of grip, and without fingers ever crossing the path of the blade do lead to DA OTF autos being extremely safe. This is particularly true on unstable or unpredictable platforms.

Let me spell it out further: We all know that a switch blade is no more dangerous than any other common pocket knife. I'm giving you reasons to present to anti-knife or knife-neutral folks to help counter the undeservedly vilified image of OTF auto opening knives. Side opening autos are an easier argument since they're easily compared to the now ubiquitous one hand manual opening folder.

*Quality =/= Expensive. I tried out a few of the Spyderco Byrd lock backs, and I really like them. They sell for $20-$30 each depending on model, and still built to Spyderco's high standards.

Blackhawk30

June 22, 2013, 07:25 AM

Slip joints are the worst types of pocket knives.They have been surpassed by the modern lock blade.I've never cut myself with a lock blade while opening or closing one.
The heavy spring pressure need to open and close slip joints causes fingers to slip and then the knife cuts you. I've broken nails whlie using the nail nick.
Deathe to slip joints.
Hail to easy opening lockblades.

hso

June 22, 2013, 08:07 AM

Oh, I agree that the fundamental design of an OTF is safest because it keeps the "piggies" out of the way.

I do wish someone would make an attractive recreational utility OTF taking from the best designs of the current batch of OTF safety cutters.